This question was previously asked in

Territorial Army Paper I : Official Practice Test Paper - 5

Option 3 : 415.68 m

**Given :**

The cliff of a mountain is 180 m. high, and the angles of depression of two ships on the either side of cliff are 30° and 60°.

**Concept used :**

tanθ = perpendicular/base

**Calculations :**

Distance between two ships is = BC + DB = CD

In ∆ABC

tan 30° = 180/BC

1/√3 = 180/BC

⇒ BC = 180√3

In ∆ ABD

tan 60° = AB/BD

⇒ BD = 180/√3 = 60√3

Distance between ships = 180√3 + 60√3 = 240√3

⇒ 415.68

**∴ Option 3 is the correct choice.**